Cave fish are unique species that live in dark, underground environments, such as caves and subterranean rivers. They have adapted to their lightless habitats by losing their eyesight and developing heightened other senses, like touch and smell. These adaptations help them navigate and find food in their challenging surroundings. One well-known example of cave fish is the Mexican tetra, which can be found in the caves of northeastern Mexico. These fish exhibit a pale coloration due to the absence of light, and their bodies are often elongated. Cave fish play an important role in their ecosystems, helping to maintain the balance of life in these secluded environments.